Abstractive Open Information Extraction

Abstract

Open Information Extraction (OpenIE) is a traditional NLP task that extracts structured information from unstructured text to be used for other downstream applications.Traditionally, OpenIE focuses on extracting the surface forms of relations as they appear in the raw text, which we term extractive OpenIE. One of the main drawbacks of this approach is that implicit semantic relations (inferred relations) can not be extracted, compromising the performance of downstream applicationsIn this paper, we broaden the scope of OpenIE relations from merely the surface form of relations to include inferred relations, which we term abstractive OpenIE. This new task calls for the development of a new abstractive OpenIE training dataset and a baseline neural model that can extract those inferred relations. We also demonstrate the necessity for a new semantics-based metric for evaluating abstractive OpenIE extractions. Via a case study on Complex QA, we demonstrate the effectiveness of abstractive OpenIE. 1 Sample Sentence Tokyo, officially Tokyo Metropolis, is the capital city of Japan and one of its 47 prefectures. Extractive {Tokyo; is; the capital city of Japan} OpenIE Extractions {Tokyo; is; one of its 47 prefectures} {Tokyo; is; the capital city of Japan} Abstractive {Tokyo; is officially; Tokyo Metropolis} OpenIE Extractions {Tokyo; is; a prefecture} or {Tokyo; is; one of Japan's 47 prefectures}